Are you starting from scratch or what? You have 2 pumps, one in the borehole, one on what looks like a hydropneumatic set. Do you know how it's all meant to work? Is the black tank in its permanent location?
One suggestion is to feed the black tank from the borehole pump, controlled on/off by level probes in the black tank. Black tank feeding the hydropneumatic set for supply to the house taps. Filter and UV kit on the hydropneumatic set discharge. BTW, I once met the boss/owner of Wedeco, one Herr Klink.
The UV might make the water fit to drink, but a good idea for you or the farmer to check the regs. I believe the water companies have to give water for public consumption a dash of chlorine (not necessarily using chlorine gas).